|HUYLER, A - Auburn University|
|CHAPPELKA, A - Auburn University|
|Prior, Stephen - Steve|
|SOMERS, G - Auburn University|
Submitted to: Urban Ecosystems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/6/2013
Publication Date: 3/11/2014
Citation: Huyler, A., Chappelka, A., Prior, S.A., Somers, G. 2014. Drivers of soil carbon in residential ‘pure lawns’ in Auburn, Alabama. Urban Ecosystems. 17:205-219.
Interpretive Summary: Metropolitan areas are expanding worldwide and residential zones are a major contributor. Because little is known about urban soil carbon (C) pools in the southeast, we performed this case study on the influence of time since lawn establishment on the soil C in residential yards in Auburn, Alabama. Four of the potential drivers for soil C were home age, yard maintenance, soil N, and soil texture. Soil C had a positive relationship with home age at the top depth. The low total soil C and diminished sequestration rate may have resulted from a positive influence of Auburn’s climate on decomposition. At lower depths, low soil C levels may have resulted from shallow rooting. The influence of time, yard maintenance, soil N and soil texture on soil C was limited or insignificant. Climatic variables and the legacy of soil C were two factors that were not measured and may have strongly influenced soil C levels. The lower than expected sequestration rates highlight the complexity of mechanisms influencing accumulation of soil C in residential lawns. To validate soil C models, additional work is needed to explore soil C dynamics across climatic regions, soil legacies, and lawn vegetation compositions.
Technical Abstract: Urban land area is expanding worldwide and may contribute to long-term carbon (C) storage; however, little is known about potential drivers of soil C storage in urban areas. Residential areas are one of the largest urban land use zones and lawns can provide stable chronosequences for studying soil C dynamics. In residential lawns containing no trees (n = 23; Auburn, AL), the relationships between soil C and four potential drivers [home age (1-51 yrs), yard maintenance practices (fertilization, irrigation, and bagging or mulching lawn clippings), soil nitrogen (N) and soil texture] were investigated. Soil C increased with home age at 0-15 cm depth by 0.026 kg C m-2 yr-1, declined by -0.011 kg C m-2 yr-1 at 15-30 cm depth, and was stable at 30-50 cm depth. Soil C had a positive relationship with soil N (R2 = 0.55) at the 0-15 cm depth. Soil C and N were not related to yard maintenance practices or soil texture. The low soil C sequestration rate and limited relationships between soil C and home age, yard maintenance, soil N and soil texture may have resulted from the positive influence of Auburn’s humid, subtropical climate on residue decomposition.